66639142 has 16 divisors (see below), whose sum is σ = 104693760. Its totient is φ = 31752072.

The previous prime is 66639113. The next prime is 66639149. The reversal of 66639142 is 24193666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66639149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10459 + ... + 15577.

It is an arithmetic number, because the mean of its divisors is an integer number (6543360).

Almost surely, 2^66639142 is an apocalyptic number.

66639142 is a deficient number, since it is larger than the sum of its proper divisors (38054618).

66639142 is a wasteful number, since it uses less digits than its factorization.

66639142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5427.

The product of its digits is 46656, while the sum is 37.

The square root of 66639142 is about 8163.2801005478. The cubic root of 66639142 is about 405.4243218291.

The spelling of 66639142 in words is "sixty-six million, six hundred thirty-nine thousand, one hundred forty-two".